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Acute inflammatory demyelinating polyneuropathy (AIDP) is the most common form of GBS, and the term is often used synonymously with GBS. It is caused by an auto-immune response directed against Schwann cell membranes.

Miller Fisher syndrome (MFS) is a rare variant of GBS. Accounting for approximately 5% of GBS cases, it manifests as a descending paralysis, proceeding in the reverse order of the more common form of GBS.[1] It usually affects the eye muscles first and presents with the triad of ophthalmoplegia, ataxia, and areflexia. The ataxia predominantly affects the gait and trunk, with the limbs relatively spared. Anti-GQ1b antibodies are present in 90% of cases.

Acute motor sensory axonal neuropathy (AMSAN) is similar to AMAN but also affects sensory nerves with severe axonal damage. Like AMAN, it is probably due to an auto-immune response directed against the axoplasm of peripheral nerves. Recovery is slow and often incomplete.[4]

Acute panautonomic neuropathy is the most rare variant of GBS, sometimes accompanied by encephalopathy. It is associated with a high mortality rate, owing to cardiovascular involvement, and associated dysrhythmias. Frequently occurring symptoms include impaired sweating, lack of tear formation, photophobia, dryness of nasal and oral mucosa, itching and peeling of skin, nausea, dysphagia, and constipation unrelieved by laxatives or alternating with diarrhea. Initial nonspecific symptoms of lethargy, fatigue, headache, and decreased initiative are followed by autonomic symptoms including orthostatic lightheadedness, blurring of vision, abdominal pain, diarrhea, dryness of eyes, and disturbed micturition. The most common symptoms at onset are related to orthostatic intolerance, as well as gastrointestinal and sudomotor dysfunction (Suarez et al. 1994). Parasympathetic impairment (abdominal pain, vomiting, constipation, ileus, urinary retention, dilated unreactive pupils; loss of accommodation) may also be observed.

Bickerstaff's brainstem encephalitis (BBE) is a further variant of Guillain–Barré syndrome. It is characterized by acute onset of ophthalmoplegia, ataxia, disturbance of consciousness, hyperreflexia or Babinski's sign. The course of the disease can be monophasic or remitting-relapsing. Large, irregular hyperintense lesions located mainly in the brainstem, especially in the pons, midbrain and medulla, are described in the literature. Despite severe initial presentation, BBE usually has a good prognosis. Magnetic resonance imaging (MRI) plays a critical role in the diagnosis of BBE. A considerable number of BBE patients have associated axonal Guillain–Barré syndrome, indicative that the two disorders are closely related and form a continuous spectrum.

The disorder is characterized by symmetrical weakness that usually affects the lower limbs first, and rapidly progresses in an ascending fashion. Patients generally notice weakness in their legs, manifesting as "rubbery legs" or legs that tend to buckle, with or without dysesthesias (numbness or tingling). As the weakness progresses upward, usually over periods of hours to days, the arms and facial muscles also become affected. Frequently, the lower cranial nerves may be affected, leading to bulbar weakness, oropharyngealdysphagia (drooling, or difficulty swallowing and/or maintaining an open airway) and respiratory difficulties. Most patients require hospitalization and about 30% require ventilatory assistance for treatment of Type II respiratory failure.[5] Facial weakness is also common. Eye movement abnormalities are not commonly seen in ascending GBS, but are a prominent feature in the Miller-Fisher variant.

Sensory loss, if present, usually takes the form of loss of proprioception (position sense) and areflexia (complete loss of deep tendon reflexes), an important feature of GBS. Loss of pain and temperature sensation is usually mild. In fact, pain is a common symptom in GBS, presenting as deep aching pain, usually in the weakened muscles, which patients compare to the pain from overexercising. These pains are self-limited and may be treated with standard analgesics. Bladder dysfunction may occur in severe cases but is usually transient.

Acute paralysis in Guillain–Barré syndrome may be related to sodium channel blocking factor in the cerebrospinal fluid (CSF). Significant issues involving intravenous salt and water administration may occur unpredictably in this patient group, resulting in SIADH, a cause of low sodium levels in the blood.

All forms of Guillain–Barré syndrome are autoimmune diseases, due to an immune response to foreign antigens (such as infectious agents) that is mistargeted at host nerve tissues instead, a phenomenon called molecular mimicry.[6] The targets of such immune attack are thought to be gangliosides, compounds naturally present in large quantities in human peripheral nerve tissues. The most common antecedent infection is the bacterium Campylobacter jejuni,[7][8] followed by cytomegalovirus (CMV).[9] However, 60% of cases do not have a known cause. Some cases may be triggered by the influenza virus, or by an immune reaction to the influenza virus.[10] There was increased incidence of Guillain-Barré syndrome following influenza immunization during the 1976-1977 swine flu pandemic;[11] however, epidemiological studies since then have demonstrated either an extremely small increased risk following immunization (under 1 additional case per million vaccinations) or no increased risk.[12][13]

The end result of this autoimmune attack on the peripheral nerves is damage to the myelin, the fatty insulating layer of the nerve, and a nerve conduction block, leading to muscle paralysis that may be accompanied by sensory or autonomic disturbances.

In mild cases, nerve axon (the long slender conducting portion of a nerve) function remains intact and recovery can be rapid if remyelination occurs. In severe cases, axonal damage occurs, and recovery depends on the regeneration of this important tissue. Approximately 80% of patients have myelin loss; in the remaining 20%, the pathological hallmark is axon loss.

Guillain–Barré, unlike disorders such as multiple sclerosis (MS) and Lou Gehrig's disease (ALS), is a peripheral nerve disorder and does not in general cause nerve damage to the brain or spinal cord.

The diagnosis of GBS usually depends on findings such as rapid development of muscle paralysis, areflexia, absence of fever, and a likely inciting event. Cerebrospinal fluid analysis (through a lumbar spinal puncture) and electrodiagnostic tests of nerves and muscles (such as nerve conduction studies) are common tests ordered in the diagnosis of GBS.

In cerebrospinal fluid, characteristic findings include albumino-cytological dissociation. As opposed to infectious causes, this is an elevated protein level (100–1000 mg/dL), without an accompanying increased cell count (absence of pleocytosis). A sustained increased white blood cell count may indicate an alternative diagnosis such as infection.

Electromyography (EMG) and nerve conduction studies (NCS) may show prolonged distal latencies, conduction slowing, conduction block, and temporal dispersion of compound action potential in demyelinating cases. F waves and H-reflexes may be prolonged or absent. Needle EMG is frequently normal in acute cases. Reduced, neuropathic recruitment in weak muscles can be seen. Fibrillations will be seen on needle EMG if there is some axonal injury after 3 to 4 weeks. In primary axonal damage, the findings include reduced amplitude of the action potentials without conduction slowing.

Features required for diagnosis are progressive weakness in legs and often arms and areflexia (the absence of deep tendon reflexes).[14][15]

Features that strongly support diagnosis are progression of symptoms over days to 4 weeks, relative symmetry of symptoms, mild sensory symptoms or signs, cranial nerve involvement (especially bilateral weakness of facial muscles), autonomic dysfunction, pain (often present), high concentration of protein in CSF, and typical electrodiagnostic features [14][15]

Features that should raise doubt about the diagnosis include severe pulmonary dysfunction with limited limb weakness at onset, severe sensory signs with limited weakness at onset, bladder or bowel dysfunction at onset, fever at onset, sharp sensory level, slow progression with limited weakness without respiratory involvement (subacute inflammatory demyelinating polyneuropathy or CIDP is more likely), marked persistent asymmetry of weakness, persistent bladder or bowel dysfunction, increased number of mononuclear cells in CSF (>50×106/L), and polymorphonuclear cells in CSF.[14][15]

Supportive care is the cornerstone of successful management in the acute patient. Of greatest concern is respiratory failure due to paralysis of the diaphragm, the muscle most important for breathing. Intubation may be needed when there is evidence of impending failure of the muscles of breathing – when the vital capacity (VC) is less than 20 ml/kg, the negative inspiratory force (NIF) is less negative (i.e., closer to zero) than -25 cmH2O, more than 30% decrease in either VC or NIF within 24 hours, rapid progression of disorder, or autonomic instability.

Subsequent treatment consists of attempting to reduce the body's attack on the nervous system, either by plasmapheresis, filtering antibodies out of the blood stream, or by administering intravenous immunoglobulins (IVIg), to neutralize harmful antibodies and inflammation causing disease. These two treatments are equally effective and a combination of the two is not significantly better than either alone. Glucocorticoids have not been found to be effective in GBS. [16][17] Treatment is usually begun as soon as the diagnosis is made. Plasmapheresis hastens recovery when used within 4 weeks of the onset of symptoms. [17] IVIg has equivalent efficacy to plasmapheresis when started within 2 weeks of the onset of symptoms, and has fewer complications. [17]
IVIg is usually used first because of its ease of administration and safety profile. The use of intravenous immunoglobulins is not without risk, occasionally causing hepatitis, or in rare cases, renal failure if used for longer than five days.

Following the acute phase, treatment often consists of rehabilitation with the help of a multidisciplinary team to focus on improving activities of daily living (ADLs). Occupational therapists may offer equipment (such as wheelchair and special cutlery) to help the patient achieve ADL independence. Physiotherapists assist to correct functional movement, avoiding harmful compensations that might have a negative effect in the long run. There is also some evidence supporting physiotherapy in helping patients with Guillain–Barré syndrome regain strength, endurance, and gait quality,[18] as well as helping them prevent contractures, bedsores, and cardiopulmonary difficulties.[19] Speech and language therapists help regain speaking and swallowing ability, especially if the patient was intubated or received a tracheostomy.

Recovery usually starts after the fourth week from the onset of the disorder. Approximately 80% of patients have a complete recovery within a few months to a year, although minor findings may persist, such as areflexia. About 5–10% recover with severe disability, with most of such cases involving severe proximal motor and sensory axonal damage with inability of axonal regeneration. Despite all improvements in treatment and supportive care, the death rate is still about 2–3% even in the best intensive care units. Worldwide, the death rate runs slightly higher (4%), mostly from a lack of availability of life support equipment during the lengthy plateau lasting four to six weeks, and in some cases up to one year, when a ventilator is needed in the worst cases. About 5–10% of patients have one or more late relapses, in which case they are then classified as having chronic inflammatory demyelinating polyneuropathy (CIDP).

Poor prognostic factors include age over 40 years, history of preceding diarrheal illness, requiring ventilator support, high anti-GM1 titre, and poor upper-limb muscle strength.

Worldwide[20], the annual incidence is about 0.6–4 occurrences per 100,000 people. Men are one and a half times more likely to be affected than women. The incidence increases with age; there are approximately 1 cases per 100,000 people aged below 30 years and about 4 cases per 100,000 in those older than 75 years.[21]
The incidence of GBS during pregnancy is 1.7 cases per 100,000 of the population.[22] Congenital and neonatal Guillain–Barré syndrome have also been reported.[23]The mean annual incidence of Guillain-Barré syndrome was 0.60 (95% confidence intervals 0.48 to 0.73) per 100,000 children under 15 years of age. There is no correlatable relationship between oral polio vaccine and GBS[24].

↑Yuki N (June 2008). [Campylobacter genes responsible for the development and determinant of clinical features of Guillain-Barré syndrome]. Nippon Rinsho. Japanese Journal of Clinical Medicine66 (6): 1205–10.

↑Davidson, I., Wilson, C., Walton, T., & Brissenden, S. (2009). Physiotherapy and guillain-barre syndrome: Results of a national survey. Physiotherapy, 95(3), 157-163.DOI:10.1016/j.physio.2009.04.001This citation will be automatically completed in the next few minutes. You can jump the queue or expand by hand

↑Karavatas, S. G. (2005). The role of neurodevelopmental sequencing in the physical therapy management of a geriatric patient with guillain-barre syndrome. Topics in Geriatric Rehabilitation, 21(2), 133-135.